Slip ring apparatus are commonly used in a variety of applications to transfer electrical energy, including electrical power and/or signals, over one or more channels between portions of an apparatus which experience relative rotation.
As a non-limiting example, slip ring apparatus may be used in a variety of downhole applications as components of apparatus which are adapted to be inserted within boreholes. Such apparatus may include without limitation, borehole drilling apparatus, wellbore completion apparatus, wellbore logging apparatus, and/or wellbore production apparatus.
A slip ring apparatus may be immersed in a dielectric fluid during its operation. The dielectric fluid creates the potential for a “hydroplaning effect” in which the dielectric fluid may cause the components of the slip ring apparatus to lose contact as they rotate relative to each other.
The potential hydroplaning effect tends to increase with the viscosity of the dielectric fluid and with the relative speed of rotation between the components of the slip ring apparatus. An increased viscosity of the dielectric fluid is a risk factor for “viscous hydroplaning.” An increased relative speed of rotation is a risk factor for “dynamic hydroplaning.”
The viscosity of the dielectric fluid in which a slip ring apparatus is immersed may vary, depending upon the operational temperature and requirements of the apparatus in which the slip ring apparatus is used and the properties of the dielectric fluid.
As the viscosity of the dielectric fluid increases and the relative speed of rotation between the components of the slip ring apparatus increases, the tendency of the components of the slip ring apparatus to lose contact due to the potential hydroplaning effect may tend to increase.